Vascular endothelial S1PR2 aggravates cardiac ischemia/reperfusion injury through triggering mitochondrial dysfunctions and endothelial pyroptosis via RHO/ROCK1/DRP1/NLRP3 pathway [heart]
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ABSTRACT: Endothelial cell dysfunction plays an essential role in the process of cardiac ischemia-reperfusion (I/R) injury. Mitochondria damage, which can trigger inflammasome activation and subsequent pyroptosis, perturbs endothelial homeostasis, leading to aggravated cardiac I/R injury. Sphingosine 1-phosphate (S1P), a bioactive lipid molecule, exerts multifaceted effect on I/R injury via its different S1P receptors. However, the effect of EC-expressing S1P receptors on endothelial dysfunction, mitochondrial damage-induced inflammasome activation and consequent pyroptosis during cardiac I/R injury remain unclear. Our findings suggest a pivotal role of EC-expressing S1PR2 to control EC mitochondrial homeostasis and demonstrate that S1PR2-meidated mitochondrial dysfunction can trigger inflammasome activation and pyroptosis in ECs, which significantly influences inflammatory responses and heart injuries following I/R.
Project description:Endothelial cell dysfunction plays an essential role in the process of cardiac ischemia-reperfusion (I/R) injury. Mitochondria damage, which can trigger inflammasome activation and subsequent pyroptosis, perturbs endothelial homeostasis, leading to aggravated cardiac I/R injury. Sphingosine 1-phosphate (S1P), a bioactive lipid molecule, exerts multifaceted effect on I/R injury via its different S1P receptors. However, the effect of EC-expressing S1P receptors on endothelial dysfunction, mitochondrial damage-induced inflammasome activation and consequent pyroptosis during cardiac I/R injury remain unclear. Our findings suggest a pivotal role of EC-expressing S1PR2 to control EC mitochondrial homeostasis and demonstrate that S1PR2-meidated mitochondrial dysfunction can trigger inflammasome activation and pyroptosis in ECs, which significantly influences inflammatory responses and heart injuries following I/R.
Project description:Increased endothelial permeability and failure to repair is the hallmark of several vascular diseases including acute lung injury (ALI). However, little is known about the intrinsic pathways that activate endothelial cell (EC) regenerative programs and thereby tissue repair. Studies have invoked a crucial role of sphingosine-1-phosphate (S1P) in resolving endothelial hyperpermeability through activation of the G-protein coupled receptor, sphingosine-1-phosphate receptor 1 (S1PR1). Here, we addressed mechanisms of generation of S1PR1+ EC, which may prevent endothelial injury. Studies were made using inducible EC-S1PR1-/- (iEC-S1PR1-/-) mice and S1PR1-GFP reporter mice to trace the generation of S1PR1+ EC. We observed in a mouse model of endotoxemia that S1P generation induced the programming of S1PR1lo to S1PR1+ EC, which comprised 80% of lung EC. The transition of these cells was required for reestablishing the endothelial barrier. We also observed that conditional deletion of S1PR1 in EC increased vascular permeability. RNA-seq analysis of S1PR1+ EC showed enrichment of genes regulating S1P synthesis and transport, sphingosine kinase 1 (SPHK1) and SPNS2, respectively. The activation of transcription factors EGR1 and STAT3 were essential for transcribing SPHK1 and SPNS2, respectively, to increase S1P production that served to amplify S1PR1+ EC transition. Transplantation of S1PR1+ EC into injured lung vasculature restored endothelial integrity. Our findings show that generation of a S1PR1+ EC population activates the endothelial regenerative program mediating vascular endothelial repair, thus raising the possibility of harnessing this pathway to restore vascular homeostasis in inflammatory injury.
Project description:Growing evidence correlated changes in bioactive sphingolipids, particularly sphingosine-1-phosphate (S1P) and ceramides, with coronary artery diseases. Furthermore, specific plasma ceramide species can predict major cardiovascular events. Dysfunction of the endothelium lining lesion-prone areas plays a pivotal role in the initiation and progression of atherosclerosis. Yet, how sphingolipid metabolism and signaling change and contribute to endothelial dysfunction and atherosclerosis remain poorly understood. By using a mouse model of coronary atherosclerosis, we demonstrated that hemodynamic stress induces an early metabolic rewiring of endothelial sphingolipid de novo biosynthesis favoring S1P signaling over ceramide as protective response. Furthermore, our data are paradigm shift from the current believe that ceramide accrual contributes to endothelial dysfunction. The de novo biosynthesis of sphingolipids is commenced by serine palmitoyltransferase (SPT), and is downregulated by NOGO-B, an ER membrane protein. We showed that Nogo-B is upregulated by hemodynamic stress in myocardial endothelial cells (EC) of ApoE-/- mice and is expressed in the endothelium lining coronary lesions in mice and human. We demonstrated that mice lacking Nogo-B specifically in EC (Nogo-A/BECKOApoE-/-) were resistant to coronary atherosclerosis development and progression, and mortality. Fibrous cap thickness was significantly increased in Nogo-A/BECKOApoE-/- mice and correlated with reduced necrotic core and macrophage infiltration. Mechanistically, the deletion of Nogo-B in EC sustained the rewiring of sphingolipid metabolism towards S1P, imparting an atheroprotective transcriptional signature that refrain coronary atherogenesis and its progression. These findings also set forth the foundation for sphingolipid-based therapeutics to reduce the treat this condition.
Project description:Glucocorticoids play a key role in metabolic adaptation during stress, such as fasting and starvation. Excess and/or chronic glucocorticoid exposure, however, cause metabolic disorders that include insulin resistance dyslipidemia and hepatic steatosis. We previously showed that chronic glucocorticoid treatment elevates hepatic production of ceramides and sphingosine-1-phosphate (S1P). Ceramides are converted to sphingosine that is further converted to S1P. We showed that ceramide-initiated signaling in turn inhibits insulin signaling and increases lipogenic program in hepatocytes. However, the role of S1P, a signaling molecule that modulates physiological responses through membrane S1P receptors (S1PRs), in glucocorticoid actions is unclear. Here we found that inhibiting S1PR2 activity, but not S1PR1 and S1PR3, resulted in improved glucocorticoid-induced insulin resistance. Similarly, reducing hepatic S1PR2 expression showed similar results. Interestingly, reducing S1PR2 expression did not affect the ability of glucocorticoids to modify insulin signaling. Instead, glucocorticoids enhanced gluconeogenesis was reduced. Moreover, glucocorticoid-induced dyslipidemia and fatty liver was also compromised in mice with reduced hepatic S1PR2 expression. Indeed, RNA sequencing analysis showed that lipogenic, gluconeogenic and glycolytic genes are significantly lower in glucocorticoid-treated hepatic S1PR2 knockdown mice than those of glucocorticoid-treated hepatic scramble small hairpin RNA (shRNA) expressing mice (Control). Overall, our studies highlight the importance role of S1PR2 signaling in the mediating glucocorticoid regulation on gluconeogenesis and hepatic lipid homeostasis.
Project description:Chronic endotheliitis and various cardiovascular co-morbidities are more likely to develop in patients who are recovering from a post-acute SARS-CoV-2 infection. Despite a growing body of clinical data suggesting that the endothelium could be the cause of both cardiac injury and the multi-organ damage found in COVID-19 patients, there is no clear link between endothelial (EC) dysfunction and increased cardiac risk during long COVID. Here, we studied long COVID-19-associated endotheliitis and its implications on cardiac dysfunction. Thrombotic vascular tissues from long COVID patients were harvested and profiled to identify the different mechanisms of viral-induced EC pathogenesis. Human induced pluripotent stem cell (iPSC)–derived ECs were leveraged to model endotheliitis in-a-dish after exposure to SARS-CoV-2, which showed similar EC dysfunction and upregulation of specific cytokines such as CCL2 and IL6, as seen in the primary ECs of long COVID patients. 3D fabricated cardiac organoids generated from iPSC-ECs and iPSC-derived cardiomyocytes (iPSC-CMs) were utilized to understand the pathological influence of endotheliitis on cardiac dysfunction. Notably, cardiac dysfunction was observed only in cardiac organoids that were fabricated with both iPSC-CMs and iPSC-ECs after exposure to SARS-CoV-2. Simultaneous profiling of chromatin accessibility and gene expression dynamics via integration of ATAC-seq and RNA-seq at a single cell resolution revealed CCL2 as the prime cytokine responsible for the non-endothelial “phenotype switching” and the impending cardiac dysfunction in cardiac organoids. This was further validated by high-throughput proteomics that showed CCL2 to be released only by cardiac organoids that were fabricated with iPSC-CMs and iPSC-ECs after SARS-CoV-2 infection. Lastly, disease modeling of the cardiac organoids as well as exposure of human ACE2 transgenic mice to SARS-CoV-2 spike proteins uncovered a putative mechanism for the cardiac dysfunction involving posttranslational modification of cardiac proteins driven by oxidative stress and inflammation. These results suggest that EC-released cytokines can contribute to the pathogenesis of long COVID-associated cardiac dysfunction, and thus a thorough clinical profiling of vascular health could help identify early signs of heart disease in COVID-19 patients.
Project description:Chronic endotheliitis and various cardiovascular co-morbidities are more likely to develop in patients who are recovering from a post-acute SARS-CoV-2 infection. Despite a growing body of clinical data suggesting that the endothelium could be the cause of both cardiac injury and the multi-organ damage found in COVID-19 patients, there is no clear link between endothelial (EC) dysfunction and increased cardiac risk during long COVID. Here, we studied long COVID-19-associated endotheliitis and its implications on cardiac dysfunction. Thrombotic vascular tissues from long COVID patients were harvested and profiled to identify the different mechanisms of viral-induced EC pathogenesis. Human induced pluripotent stem cell (iPSC)–derived ECs were leveraged to model endotheliitis in-a-dish after exposure to SARS-CoV-2, which showed similar EC dysfunction and upregulation of specific cytokines such as CCL2 and IL6, as seen in the primary ECs of long COVID patients. 3D fabricated cardiac organoids generated from iPSC-ECs and iPSC-derived cardiomyocytes (iPSC-CMs) were utilized to understand the pathological influence of endotheliitis on cardiac dysfunction. Notably, cardiac dysfunction was observed only in cardiac organoids that were fabricated with both iPSC-CMs and iPSC-ECs after exposure to SARS-CoV-2. Simultaneous profiling of chromatin accessibility and gene expression dynamics via integration of ATAC-seq and RNA-seq at a single cell resolution revealed CCL2 as the prime cytokine responsible for the non-endothelial “phenotype switching” and the impending cardiac dysfunction in cardiac organoids. This was further validated by high-throughput proteomics that showed CCL2 to be released only by cardiac organoids that were fabricated with iPSC-CMs and iPSC-ECs after SARS-CoV-2 infection. Lastly, disease modeling of the cardiac organoids as well as exposure of human ACE2 transgenic mice to SARS-CoV-2 spike proteins uncovered a putative mechanism for the cardiac dysfunction involving posttranslational modification of cardiac proteins driven by oxidative stress and inflammation. These results suggest that EC-released cytokines can contribute to the pathogenesis of long COVID-associated cardiac dysfunction, and thus a thorough clinical profiling of vascular health could help identify early signs of heart disease in COVID-19 patients.
Project description:Chronic endotheliitis and various cardiovascular co-morbidities are more likely to develop in patients who are recovering from a post-acute SARS-CoV-2 infection. Despite a growing body of clinical data suggesting that the endothelium could be the cause of both cardiac injury and the multi-organ damage found in COVID-19 patients, there is no clear link between endothelial (EC) dysfunction and increased cardiac risk during long COVID. Here, we studied long COVID-19-associated endotheliitis and its implications on cardiac dysfunction. Thrombotic vascular tissues from long COVID patients were harvested and profiled to identify the different mechanisms of viral-induced EC pathogenesis. Human induced pluripotent stem cell (iPSC)–derived ECs were leveraged to model endotheliitis in-a-dish after exposure to SARS-CoV-2, which showed similar EC dysfunction and upregulation of specific cytokines such as CCL2 and IL6, as seen in the primary ECs of long COVID patients. 3D fabricated cardiac organoids generated from iPSC-ECs and iPSC-derived cardiomyocytes (iPSC-CMs) were utilized to understand the pathological influence of endotheliitis on cardiac dysfunction. Notably, cardiac dysfunction was observed only in cardiac organoids that were fabricated with both iPSC-CMs and iPSC-ECs after exposure to SARS-CoV-2. Simultaneous profiling of chromatin accessibility and gene expression dynamics via integration of ATAC-seq and RNA-seq at a single cell resolution revealed CCL2 as the prime cytokine responsible for the non-endothelial “phenotype switching” and the impending cardiac dysfunction in cardiac organoids. This was further validated by high-throughput proteomics that showed CCL2 to be released only by cardiac organoids that were fabricated with iPSC-CMs and iPSC-ECs after SARS-CoV-2 infection. Lastly, disease modeling of the cardiac organoids as well as exposure of human ACE2 transgenic mice to SARS-CoV-2 spike proteins uncovered a putative mechanism for the cardiac dysfunction involving posttranslational modification of cardiac proteins driven by oxidative stress and inflammation. These results suggest that EC-released cytokines can contribute to the pathogenesis of long COVID-associated cardiac dysfunction, and thus a thorough clinical profiling of vascular health could help identify early signs of heart disease in COVID-19 patients.
Project description:Chronic endotheliitis and various cardiovascular co-morbidities are more likely to develop in patients who are recovering from a post-acute SARS-CoV-2 infection. Despite a growing body of clinical data suggesting that the endothelium could be the cause of both cardiac injury and the multi-organ damage found in COVID-19 patients, there is no clear link between endothelial (EC) dysfunction and increased cardiac risk during long COVID. Here, we studied long COVID-19-associated endotheliitis and its implications on cardiac dysfunction. Thrombotic vascular tissues from long COVID patients were harvested and profiled to identify the different mechanisms of viral-induced EC pathogenesis. Human induced pluripotent stem cell (iPSC)–derived ECs were leveraged to model endotheliitis in-a-dish after exposure to SARS-CoV-2, which showed similar EC dysfunction and upregulation of specific cytokines such as CCL2 and IL6, as seen in the primary ECs of long COVID patients. 3D fabricated cardiac organoids generated from iPSC-ECs and iPSC-derived cardiomyocytes (iPSC-CMs) were utilized to understand the pathological influence of endotheliitis on cardiac dysfunction. Notably, cardiac dysfunction was observed only in cardiac organoids that were fabricated with both iPSC-CMs and iPSC-ECs after exposure to SARS-CoV-2. Simultaneous profiling of chromatin accessibility and gene expression dynamics via integration of ATAC-seq and RNA-seq at a single cell resolution revealed CCL2 as the prime cytokine responsible for the non-endothelial “phenotype switching” and the impending cardiac dysfunction in cardiac organoids. This was further validated by high-throughput proteomics that showed CCL2 to be released only by cardiac organoids that were fabricated with iPSC-CMs and iPSC-ECs after SARS-CoV-2 infection. Lastly, disease modeling of the cardiac organoids as well as exposure of human ACE2 transgenic mice to SARS-CoV-2 spike proteins uncovered a putative mechanism for the cardiac dysfunction involving posttranslational modification of cardiac proteins driven by oxidative stress and inflammation. These results suggest that EC-released cytokines can contribute to the pathogenesis of long COVID-associated cardiac dysfunction, and thus a thorough clinical profiling of vascular health could help identify early signs of heart disease in COVID-19 patients.